Racking mechanism for knitting machines



Oct. 18, 1938.

' F. ECK

RACKING MECHANTSM FOR KNT'FFTNG MACHINES Filed March 31, 1956 3 Sheets-Sheet l INVENTOR FRfl/Vk ECK ATTORNEYS Oct. 18, 1938. ECK 2,133,688

RACKING MECHANISM FOR KNITTING MACHINES Filed March 51, 1936 3 Sheets-Sheet 2 m r w lv gmamd.

ATTORNEY Oct. 18, 1938. c

RACKING MECHANISM FOR KNITTING MACHINES Filed March 51, 1936 3 Sht$-$h8t 5 ow, ATTOR N EYS Patented Oct. 18, 1938 UNITED STATES PATENT OFFICE BACKING MECHANISM FOR KNITTING MACHINES 12 Claims.

This invention relates to racking mechanism and machine opening mechanism for knitting machines which, in the production of certain designs, are racked.

Certain types of knitting machines have two needle boards which are located relatively close to each other. These needle boards have grooves in which are disposed the knitting needles. Under the control of certain mechanisms, the needles are moved back and forth on machines with inclined needle boards, and from one needle board to the other on machines with fiat needle boards.

In knitting many fabrics, the design calls for what is known in the art as the rack stitch. The rack stitch is produced by shifting the needle boards longitudinally with respect to each other. This is termed racking. Depending on the design, the racking may take place over any number of needles. That is, the board that is shifted is 20 moved over a desired distance (i. e. number of needles), and in the type with fiat needle boards, must be stopped in an exact position so that the grooves from one needle board are exactly in line with the grooves of the other needle board.

In the prior art, this shifting and stopping is produced by impounding members on stepped arms which are shifted in an opposite direction by a gear, or the shifting is done directly by a gear. A gear, however, requires a certain amount of clearance which becomes greater with use due to wear. In some instances, the shifting of the needle boards is produced by eccentrics, which eliminate all clearance. However, the amount of shifting by eccentrics is limited to two or four needles.

Objects of this invention are to combine the advantages of eccentrics with a selective racking mechanism, so that the machine may be racked, by eccentrics, over twelve needles or more, if desired; over any desired number of needles at a time; to start and stop the needle boards at any desired and exact position and rack the needle boards in either direction.

Heretofore, on power driven machines, the

amount of shift of the needle boards is controlled by an endless chain carried on a sprocket Wheel which in turn is controlled by a timing mechanism. The control is effected by the use of links of different heights whereby the boards are shifted different distances during one operation. Thus, as many different shiftings of the needle board can be obtained as there are links of different heights on the endless chain. According to this invention, also, a greater number of racking positions are obtained than the number of links of diiferent height on the endless chain.

The invention also seeks, in another aspect, to adjust the eccentric. To this end, the functions of two eccentrics are combined with a sliding rack control mechanism.

As already pointed out, on machines with flat needle boards, the needles are shifted from one needle board to the other during the knitting operation. By means of certain adjustments on the needle shifting mechanism, some of the needles on one needle board may be shifted to the other needle board while the rest of the needles remain on the first mentioned needle board. Thus there are needles on each board. The rack stitch is produced by shifting one of the needle boards longitudinally with respect to the other when there are needles on both boards. As the needles extend beyond the edge of the needle boards, the needles may interlock with each other during racking and thus be damaged. To avoid this, it is advantageous to move the needle board further apart during this operation. This lateral shifting of the boards is termed opening the machine. Although a greater opening offers less chance for the needles to interlock, which is to be avoided, nevertheless, the further apart the needle boards are moved, the further the fabric must be pulled by the needles. As the tightness of the knit of the knitted fabric differs from place to place therein, if the fabric is tight and the machine is opened too far, some of the needles may be pulled back by the fabric and thus be in a position to interlock with needles on the other board. Therefore, for the best operation, a compromise is sought, in which the machine is opened enough for the needles but not too much for the fabric. In the prior art, the amount of opening is consistent regardless of the tightness of the fabric. A further object of this invention is, therefore, to open the machine a selective distance depending on the tightness of the fabric. To this end, easily adjustable means are provided to open the machine.

These and other objects of the invention and the means for their attainment will be more apparent from the following detailed description taken in connection with the accompanying drawings illustrating one embodiment by which the invention may be realized and in which:

Figure 1 is a View in perspective showing so much of a knitting machine as is necessary to illustrate the racking and machine opening, position setting and position controlling devices of this invention;

Figure 2 is an exploded view, in perspective, showing the four parts forming the adjustable eccentric of Figure 1;

Figure 3 is a fragmentary sectional view, taken in the plane indicated by the line 3--3 of Figure 1, looking in the direction of the arrows and showing the position assuring device;

Figure 4 is a view, in perspective, showing mechanism for setting the racking and machine opening mechanisms into neutral position and also the machine opening devices at both ends of the machine and their interconnections;

Figure 5 is a sectional view, taken on the line 55 of Figure 1;

Figure 6 is a plan view of the knitting machine of this invention looking from above and showing the relation of the different parts;

Figure '1 is a view in front elevation, of the knitting machine of this invention showing the relation of the different parts;

Figure 8 is a front view showing the controlling block and illustrates the different positions which the controlling pin assumes when this block is shifted vertically; and

Figure 9 is a diagrammatic view showing the different positions which the rollers assume in setting the racking mechanism into different positions.

Referring first to Figure 1, the needle board 4| is the relatively stationary needle board and the needle board 40 is shifted with respect thereto whereby selected needles may be transferred from the needle grooves of one board to the other as desired. Needle board 40 is shifted or reciprocated by a racking member 13, 34 suitably supported for reciprocation by a bracket 34 extending upwardly from a bed plate or base B of the apparatus. The racking member 13, 34 is reciprocated axially through the instrumentality of eccentric means 25, 28, 32, 33 actuated from timing mechanism, not shown because forming no part of this invention, but causing the periodic reciprocation of pull rods 8 and 39. The rod 6 carries the pawl 9 which periodically turns the ratchet 5 on a shaft 6 carrying sprockets I and 2. The rod 39 carries the pawl 39 which periodically turns the ratchet 31 on the shaft 38.

On the sprocket wheels I and 2 are mounted endless chains 3 and 4. These endless chains usually comprise links of different heights which effect control of the mechanism. Sprocket wheels I and 2 and ratchet wheel 5 are fixed on the axle '6, this axle being rotatably mounted in frame I. When driving arm 8 for ratchet wheel 5, controlled by a timing device, is moved backward, (to the right as viewed) hook 9 engages ratchet wheel 5 and rotates it through an angular distance equal to one tooth on the wheel 5. The distances of the teeth on wheel 5 are so selected as to be equal to the length of one link on the endless chains. Thus, when wheel 5 is rotated by one stroke of arm 8, the sprocket wheels I and 2 rotate just enough to bring the next link under rollers I 0, and II. Roller I0 is mounted on the end of a plunger I2 slidable in a guide I2 shown carried with bracket 1.

If a link on chain 3, which is higher than the link then under roller Ill, c0mes under roller I0, this roller, its supporting plunger I2 and the plate I3, fixed to plunger I2, are elevated through a distance equal to the difference in height of the two adjacent links on chain 3. On plate I3 rests a roller I4 which is held tightly on plate I3 by a spring I 5, so that roller I4 is raised or lowered the same amount as plate I3 each time a successive link comes under roller I0. Roller I4 is mounted on the horizontal arm I 6 of the bell-crank-like member I6, I6 pivoted on a pin I1 extending through blocks I8 disposed on opposite sides of a block 20 slidable in the guides 1' on bracket 1. The pin I1 also passes through and is guided in a slot IS in the block 20. Block I8 retards pin l1 from vertical movement and block 20 from longitudinal movement and both blocks I8 and block 20 prevent the pin and bell crank I6, I6 from lateral movement. Thus pivot I1 rotates in its original position so that the roller 2| on the depending arm I6 is moved to the right an amount proportional to the lengths of the two arms of member I6, I6.

The roller 2I, being disposed in a housing 22 on a reciprocating rod 23, a movement to the right of roller 2'! forces the housing 22 and rod 23 to the right also. The rod 23 carries a bearing 24 for a shaft 25 rotatably mounted therein. Thus a movement to the right of bearing 24 carries rod '25 to the right also and also carries with it pivot pin 26 connecting the upper end of shaft 25 with a rotatable disc 21. The disc 21 is disposed in a slide 28 adapted to reciprocate in the guideways 3|. Pivot pin 26 can only move longitudinally in the same horizontal line. Therefore, disc 21 rotates in the block 28 and due to the changed position of pivot 26 with respect to the center of disc 21, block 28 slides downwardly. A pin 29 on shaft 25 slides in an arcuate groove 30 in the block 28 and is always vertically under the pin 26. Therefore, both pins 29 and 26 have the same eccentricity with respect to the center of disc 21. The groove 30 is so constructed that pin 29 can slide in it laterally while block 28 slides vertically. Disc 21 is preferably, but not necessarily, mounted on ball bearings within block 26.

The frame 3|, in which block 28 is slidable, is fixed to a circular disc or roller 32. Disc 32 in an aperture 32' is housed in a rectangular block 33 which is preferably horizontally slidable in contact with the needle board shifting member 34, say, by being disposed in transverse guideways thereof.

On the lower end of shaft 25 is fixed a bevel gear 35 which is driven by bevel gear 36 which, with the ratchet wheel 31, are fixed to shaft 38, the ratchet wheel 31 being turned by pull arm 39 which is driven by a. timing mechanism, not shown.

When pull arm 39 rotates ratchet wheel 31, by making one stroke, gear 36 is rotated the same amount. Gears 35 and 36 are so proportioned that the amount of rotation of gear 36, due to one stroke, rotates gear 35 through one-half revolution. This action also rotates disc 21 and thus disc 32 through one-half revolution. Assuming that, before such rotation, pivot pin 26 was eccentrically disposed with respect to disc 21, discs 21 and 32 rotate in a vertical line with pivot 26 as a center, and thus after one-half revolution, the centers of these discs, which are always in the same vertical line, are brought to the other side of pivot 26 and thus disc 32 is actually moved longitudinally. Since the disc 32 is operatlvely connected with member 13 through block 33, member 13 is moved longitudinally by rotation of disc 32 about its offset axis. Member 13 is connected to needle board 40, thus the needle board is also shifted, which performs the racking operation. During this operation, needle board 4| is stationary and, therefore, different grooves 42 are brought into register.

Thus there has been described the operation of the invention from the controlling chain 3 to the needle boards.

The operation for obtaining a desired distance (number of needles) in racking will now be described.

If the parts of the mechanism are proportioned so that the difference of height between two consecutive links on chain 3 sets pivot 26 to an eccentricity of one-half needle distance, after onehalf revolution, the needle board is racked over one needle distance. If the difference of height between the two links is twice as much, pivot 26 is set to an eccentricity of two half needles and the machine is racked over two needles. Therefore, as many times a half needle eccentricity can be produced as there are links of different height on chain 3. Thus, if it is desired to rack the machine over twelve needles in one direction, twelve links of different height are required and twelve links to rack the machine in the opposite direction, that is twenty-four links of different height are required. As it is possible, but, in most situations is found to be impractical, to use twenty-four links of different height, a second chain 4 is provided to act in conjunction with chain 3.

If, on chain 3, the highest link is under the roller 10, bell crank l6, l6 and rollers l4 and 2| assume a certain position, as shown in Figure 1. Roller 14 is at the position indicated at 43, (Figure 9) while roller 2! is at the position indicated at 44 and pivot 11 at the position indicated at 45. Assuming that, on chain 4, a higher link comes under the roller H and on chain 3 the lowest link, which follows the highest link comes, at the same time, under roller 10, plunger 41 having roller 48 at its upper end, is moved upwardly (Figure 1). Roller 49 pushes arm 49, pivoted on the guide l2, and with it roller 50, at its end, upwardly. Roller 59 is in contact with block 20 in which is the slot l9, best shown in Figure 8. When block 20 is thus moved upwardly, pivot l1 slides in slot i9 and assumes the position indicated at 53, Figures 8 and 9, while roller [4 moves from position 43, Figure 9, to position 54 and roller 2| remains at position 44, Figure 9. Thus with pivot I I at position 53, rollers l4 and 2! can assume as many different positions as there are links of different heights on chain 3. Thus by using on chain 4, four links, for instance, of different height, pivot I! can assume the four different positions 45, 53, 55 and 56, Figure 9, and if there are six links of different height on chain 3, rollers l4 and 2| assume six different positions for every position of roller 2!. Therefore, four times six or twenty-four positions can be assumed by pivot I1. Due to these twenty-four positions, the machine is racked over twelve needles with only ten links of different heights, four on one chain, say chain 4, and six on the other chain, say chain 3, that is, over a greater number of needles than the number of links of different heights used.

When the links in operative position under rollers l0 and I! are such that a lower link on chain 3 follows the preceding relatively higher link, roller I0 is caused to follow the links on the chain by spring l5 pulling arm l6 downwardly and racking the machine in the opposite direction. The operation in opening the machine a selective distance will now be described.

The opening of the machine is simultaneous with the racking. Therefore, the opening device is controlled by the racking means. Pull arm 39, as can be best seen in Figure 4, which produces the racking operation by rotating ratchet wheel 31, is fixed to an arm 51 to which is fixed an arm 58. Arm 58 has a raised part 59, which comes in contact with roller 60 on a bell crank 6|, 6|, fixed on rock shaft 62, When arm 58 is pulled to the right. This elevated part 59 is too high to slide under roller 60. Therefore, the roller 60 is moved to the right and thereby the arm BI is swung in a counter-clockwise direction, as viewed. The arm 6| has a bearing end 61a which, during this movement, pushes a block 63 upwardly. The block 63 is slidable in guideways 63' and is formed with a slot or groove 65. Pin 64 on a bifurcated link 66 slides in the vertical, diagonal, vertical groove 65 and thereby comes from the vertical groove through the diagonal groove to the other vertical groove 65, whereby pin 64 and link 66 are moved to the left, as viewed. Link 66 is adjustably pinned to a forked member 61, by a pin 88. The forked member 61 is pivotally connected at pivot '10 to a block 69. Forked arm 67 is pivotally connected to standard H, as at 12. Block 69 is formed with teeth 12' on one face, which teeth 72 engage in similar teeth 13' on member '!3 which is fixed to the shiftable needle board 46.

There is one member 13 at each end of the needle board 49 together with a counterpart of the block 63 and link 65 and associated mechanism, the block 63 at the other end being moved by an arm 61, fila on the rock shaft 62 which is the equivalent of the members bearing the same reference characters on the bell crank 6!. When link 66 and forks 61 are pushed to the left, as viewed, block 69 first disengages from the teeth 13 of racking member 13 and on further movement comes in contact with the other face 13a of the member 13, and pushes it backward, which serves to open the machine, that is, separate the needle boards. The machine is then racked. By the time the racking operation is completed, elevated part 59 on arm 58 is moved such distance as not to be under roller 60 on the opening bal crank 5!, 6i. Block 63 is therefore no longer held upwardly by bell crank 61, but is forced downwardly to its lowermost position by spring 14, so that pivot 64 and all other members controlled by it assume their original positions and the machine is closed and locked again by engagement of the teeth i2, 13.

The degree of opening of the machine is determined by the position of the pin 68. Thus to open the machine a greater distance, arm 66 is pinned at a lower position such as by passing the pin 68 through the hole 75. As diagrammatically shown in Figure 5, if the connection is as shown, pin 68 assumes position 16 and pivot '59 assumes position H. If arm 65 is pinned at position '15, it assumes the position 78 after opening, which position is directly under position 16, and pivot it assumes the position F9 which is further out than the position 11. Therefore, the machine is opened a greater distance. In changing the positions of pinning of arm 66, the distance between pivot 64 and pin 68 changes. To permit this, arm 56 is extensible, preferably by being provided with the adjustable joint 80.

As thus far explained, the machine would be racked and opened in each round. Since the design may call for stitches without rack, it would be impractical to open the machine except when necessary. Therefore, the mechanism is made capable of being set into neutral or out of work position as can best be seen in Figure 8, when block 29 is raised beyond the point where pivot I'I occupies position 56, pivot I1 is not effected. But if block 20 is raised high enough so that pivot II assumes position 82, the upper part of block 20 forces lever arm 83 (Figure 4) upwardly. Since lever 83 is pivoted at 84, say on guideway I, the other end 83' presses plunger 85 downwardly. When block 20 is lowered so that pivot I'I assumes position 86 (Figure 8), the lower part of block 20 comes in contact with the end of arm 81 (Fig. 4), and pushes it down. Lever 81, 81' is pivoted at 88, say, on a. convenient part of the machine. Therefore, the other end of arm 81' is raised, which raises plunger 89 and thus lever arm 83. Therefore again plunger 85 is pushed down the same as when block 20 is raised to its highest position. Thus, there are two positions of block 20 which may be utilized to set the machine into neutral. When plunger 85 is pushed down, arm 90 of lever 90, 90 is also pushed down. Lever 90, 90' is pivoted at 9|, therefore the other end 90 is raised. Arm 90 being in contact with arm 93 of lever 93, 93 at the extension 92, and the lever 93, 93' being pivoted at 94, the end of arm 93 is raised by the extension 92. Arm 93 has a downward extension hook 95 over which slides pull arm 39. When the end of arm 93 is raised, hook 95 raises pull rod 39 so that it does not engage ratchet wheel 31 and thus the machine is not racked. When the end of arm 93 is raised, the other end, 93', opposite the pivot 94 is lowered and presses down on arm SI of the opening bell crank 6|, 6|, thereby rotating arm BI and bringing roller 60 into such a raised position that the elevated part 59 of arm 58 can pass beneath it. Therefore, the machine is not opened.

Any position in which the eccentric 29-33 may be set, may not be exact because roller 2| and pivot I! each have some clearance. Therefore, means is provided for securing an exact position of the eccentric. Reference is again made to Figure 1. Since racking is controlled by the endless chains and, therefore, by pull arm 8, the obtainment of an exact position is also controlled by arm 8, according to the illustrated embodiment. To arm 8 is connected an arm 96 which has an elevated part 91. When arm 8 is retracted, this elevated part 91 comes in contact with roller 98 on a bell crank 99, 99' which is pivoted to a part of the frame by a pivot I and arm 99 is rotated about pivot I00 in a counter-clockwise direction, as viewed in Figure 3. The other arm 99' is rotated upwardly and with it pin I0 I, which connects the lower end of the two arms I02 is also raised. To arms I02 are pivoted, as at I04, links I03. The other extremities of the links I03 are pinned together at I05. The upper ends of links I03 are in contact with a stationary bar I06. Therefore, when the pin IOI connecting the lower ends of arms I02 is pushed upwardly, the pivots I04 move outwardly. When pivots I04 move outwardly, the upper extremities of arms I02 and the teeth I04 thereon also move outwardly a distance suflicient to disengage from the teeth III! on sliding block I08. The block I08 is then free to slide on the bar I06. Block 24, bearing on the reciprocating rod 23, is formed with extensions I09 between which is slidably mounted a block IIO (Figure 6). Block H0 is pivotally connected, as at I I3, to one end of a lever I I2, which is pivoted at H4 and at the other end, arm H2 is similarly pivoted to a block II5, as at IIG. When block 24, and thus the whole racking mechanism, is

moved in one direction, the other end of arm II2 moves in the opposite direction and stops at a position controlled by the racking mechanism. If the racking mechanism is a little off, position arm I02 will not register with a tooth IN on sliding block I08. However, when the elevated part 91 on arm 96 is away from roller 98 and pin I is no longer held upwardly, spring III pulls the arms I02 together to cause the teeth to engage. If a tooth I0'I does not correspond exactly with a notch on the slide I 08, the sides of I02 force the sliding block I08 into the proper position to bring the racking mechanism into an exact position.

The structure and operation of the racking mechanism for knitting machines according to this invention will be apparent from the foregoing description.

Various modifications will occur to those skilled in the art in the disposition and configuration of the component elements going to make up the invention as a whole, as well as in the use of equivalent movements and instrumentalities, and no limitation is intended by U phraseology of the foregoing description or linutations in the accompanying drawings, except as indicated in the appended claims.

What is claimed is:

1. In a knitting machine, in combination two needle boards, reciprocating means to shift one of the needle boards with respect to the other, a member movable transversely on said reciprocating means and formed with an aperture, a circular disc in the aperture, guideways fixed on the circular disc in a plane perpendicular to the transversely movable member, a member movable in said guideways formed with an aperture, 8. circular disc in said aperture, a rod reciprocable in the plane of the last named member, having a bearing, a shaft journalled therein operatively connected with the last named member and eccentrically with the last named circular disc, means to periodically rotate said shaft, means to reciprocate the rod axially, comprising a bellcrank, one arm of which is connected with the rod, and means to adjust the position of the other arm of the bell-crank.

2. In a knitting machine, the combination of cooperating needle boards, means to open the needle boards by moving one away from the 59 other, means to rack the same need e board that is moved and means to selectively control the extent of separation and racking of the needle boards.

3. Racking mechanism for knitting machines comprising, the combination with a relatively stationary needle board and a shiftable needle board, of means to control the amount of the shift of the needle board comprising a pivotally mounted bell-crank, guiding means for the pivot, means to adjust the position of the guiding means, and means to adjust the angular position of the bell crank about the pivot comprising an endless chain having links of varying height,

and operative connections between a link and tive connections between a link and the slotted member, and means to adjust the angular position of the bell-crank about the pivot comprising an endless chain having links of varying height, respectively, and operative connections between a link and an arm of the bell-crank.

5. In knitting machines, the combination with a relatively stationary needle board, a needle board movable with respect thereto and racking mechanism for the same needle board, of opening mechanism for separating the needle boards comprising means operable by the racking mechanism.

6. In knitting machines, the combination with a relatively stationary needle board, a needle board movable with respect thereto and racking mechanism for the same needle board, of opening mechanism for separating the needle boards comprising adjustable means operable by the racking mechanism.

'7. Racking mechanism for knitting machines comprising the combination with a relatively stationary needle board and a shiftable needle board, of means to shift the needle board comprising a pivoted member, a movable fulcrum for said pivoted member, movable means to move said pivoted member and movable means to move said fulcrum, said last named means being so related that said shiftable needle board is caused to occupy a greater number of positions than the sum of the positions occupied by said two last named means.

8. The combination of a first disc and a first block in which said disc is rotatably mounted, guide means for said first block, a second disc and a second block in which said second disc is rotatably mounted, perpendicular extensions from said first disc forming guide means for said second block and means for rotating said second disc on an axis in the plane of said second disc to reciprocate said first block in its guide means.

9. A mechanism for changing rotary motion into a variable stroke reciprocal motion com prising a reciprocating member, a block mounted for transverse movement on said reciprocating member provided with a circular opening, a circular disc mounted in said opening, guide members projecting vertically from the said disc, a second block mounted for vertical movement in said guide members and provided with a circular opening, a second circular disc in said second block, a rotatable rod pivoted to said second disc at a point away from the center of said second disc, means for adjusting the position of said rod in a path parallel to that of the reciprocating member and means for rotating said rod in any of its adjusted positions.

10. A racking mechanism for a knitting machine comprising a reciprocating member attached to a movable needle board, a block mounted for transverse movement on said reciprocating member provided with a circular opening, a circular disc mounted in said opening, guide members projecting vertically from the said disc, a second block mounted for vertical movement in said guide members and provided with a circular opening, a second circular disc in said second block, a rotatable rod pivoted to said second disc at a point away from the center of said second disc, means for adjusting the position of said rod in a path parallel to that of the reciprocating member and means for rotating said rod in any of its adjusted positions.

11. A mechanism for changing rotary motion into a variable stroke reciprocal motion comprising a reciprocating member, a block mounted for transverse movement on said reciprocating member provided with a circular opening, a circular disc mounted in said opening, guide members projecting vertically from the said disc, a second block mounted for vertical movement in said guide members and provided with a circular opening, a second circular disc in said second block, a rotatable rod pivoted in said second disc at a point away from the center of said second disc, means for adjusting the position of said rod in a path parallel to that of the reciprocating member to insure movement of the needle board the exact distance corresponding to the number of needles racked.

12. A racking mechanism for a loom comprising a reciprocating member, a block mounted for transverse movement on said reciprocating member provided with a circular opening, a circular disc mounted in said opening, guide members projecting vertically from the said disc, a second block mounted for vertical movement in said guide members and provided with a circular opening, a second circular disc in said second block, a rotatable rod pivoted to said second disc at a point away from the center of said second disc, means for adjusting the position of said rod in a path parallel to that of the reciprocating member, of means to control the amount of the shift of the rod and thereby the needle board comprising a pivotally mounted bell-crank, guiding means for the pivot, means to adjust the position of the guiding means, and means to adjust the angular position of the bell-crank about the pivot comprising an endless chain having links of varying height, and operative connections between a link and of an arm of the bellcrank.

FRANK ECK. 

